The air quality in the Indian cities deteriorated Monday, 13 November — a day after the country celebrated Deepavali.
The 12-hour average PM2.5 levels (levels of airborne particulate matter that are 2.5 microns or less in diameter) were recorded at 114.7 g/m3 (micrograms per cubic metres) in Chennai, according to data released by Climate Trends.
The research-based consulting and capacity-building initiative — which says it aims to bring greater focus on issues of environment, climate change, and sustainable development — also said that PM2.5 levels in Hyderabad stayed at 88.4 g/m3, and Bengaluru at 68.1 g/m3.
The daily standard limit of PM2.5 levels, as per the World Health Organisation, is 15 g/m3.
Bengaluru, which will be celebrating the festival of lights on 14 November as well, has already exceeded the limit.
The city-wise levels
Last year, Hyderabad’s daily average PM2.5 levels recorded on 25 October (a day after Deepavali that year) was 65.1 g/m3. The equivalent for Bengaluru and Chennai was 81.4 and 89.3 g/m3, respectively.
Hyderabad and Chennai showed an increase in PM2.5 levels. “It is unfair to say Bengaluru recorded less pollution levels, as the bursting of fireworks would be at its full intensity only tomorrow,” an official from the Karnataka State Pollution Control Board (KSPCB) told South First.
The average Air Quality Index (AQI) in Chennai City ranged between 207 (poor) to 365 (very poor), as per observations from 6 am on 12 November to 6 am on 13 November.
This could be attributed to the large number of people indulging in bursting of firecrackers and high relative humidity and low wind speed, said the Tamil Nadu Pollution Control Board (TNPCB) in a statement.
“Adding to this, meteorological conditions were not in favour of Chennai. The wind speed was poor on Sunday, and so, pollutants were sustained for a long time,” said TNPCB Deputy Director Sankara Subramanian.
An analysis of the data from 2019 to 2022 shows that Bengaluru has been performing better than Chennai and Hyderabad, in terms of restricting Deepavali-related pollution. The highest PM2.5 levels recorded post-Deepavali in Bengaluru was 81 g/m3 in 2022, while Hyderabad recorded 89 g/m3, and Chennai a whopping 117 g/m3.
“At least 60 percent of the crackers in Hyderabad are green. To create awareness on the environment, including air pollution, the Telangana State Pollution Control Board (TSPCB) is spending ₹1 crore annually on the state, centred around Hyderabad,” said TSPCB Senior Social Scientist Dr WG Prasanna Kumar.
“In other countries, those responsible for heavily polluting sources have been put behind bars. The meteoric rise of PM2.5 levels during the last two days shows firecrackers revelry has taken over,” said Climate Trends Director Aarti Khosla.
“While these spikes last only for a few hours or days, such high levels of air pollution add to the exposure burden on human health, which is already high in Indian cities,” she added.
Weather plays a role
In 2022, a number of areas in Chennai reported air quality in the “severe” range, which meant a pollution level that is worse than poor and very poor categories, the TNPCB release mentioned.
While the TNPCB officials attributed the pollution in the city to the high relative humidity, experts had a different perspective.
“Chennai experienced rain before the festival, which significantly washed out the suspended particulate matter from the air. Whatever the pollution we are noticing in Chennai can be attributed to crackers directly, in addition to some local regular sources like vehicles,” said Climate Trends Technical Lead (Air Quality) Dr Palak Balyan.
“On the other hand, Hyderabad’s air is usually dry, resulting in resuspension of particles in the air. The hilly terrain in the city results in the movement of pollution from upward regions to downward slopes,” she added.
“Similar trends of rising pollution, away from the festival season, are being observed in several southern cities. It is time for increasing awareness among citizens before the problem escalates to what the national capital has witnessed,” said Balyan.
The Bengaluru story
While it is still early to say Bengaluru has been one of the least polluted cities during Deepavali as the city is celebrating the festival on 14 November as well, patterns suggest that the city has been effectively reducing bursting of fireworks.
On 12 November, only three cities — Bengaluru, Delhi, and Gandhinagar — had PM2.5 levels lower than those on Deepavali in 2022, that is, on 24 October, according to the Climate Trends report.
Bengaluru recorded lower PM2.5 averages in 2023 as compared to 2022 for the day before, the day of, and the day after Deepavali (for 2023, only data from 12 am to 12 pm of 13 November was available).
Additionally, on the day after Deepavali (12-hour average), it recorded the lowest PM2.5 average among the 11 cities analysed in the report.
Ravi Srivastava, a Bengaluru resident, posted on X that he was “very happy” to share that Bengaluru was observing near-zero bursting of crackers. He added that he could “vouch for” Koramangala and a radius of 5 km where this was happening.
very happy to share that Bengaluru is observing near'Zero' Bursting of Fire crackers, during Peak hour8-10 PM the sound is minimal.I can vouch for #Koramangla &radius of 5KM
Appreciate citizenary to observe "No Cracker Policy" & sensitivity towards Pollution @siddaramaiah pic.twitter.com/9RS8ZUKzOb
— Ravi Srivastava 🇮🇳 रविश्रीवास्तव🐤 (@ravi4354) November 13, 2023
It may be noted that the KSPCB directed citizens in the state to burst firecrackers between 8 pm and 10 pm.
“The regulation was followed by many resident welfare associations who sensitised their citizens. It was usual to hear continuous sounds of crackers for three days in Bengaluru. But, this year, I could hear it only during evenings,” said Sudha Rani, a Bengaluru citizen.
The KSPCB also constituted a task force in Bengaluru to crack down on the illegal sale of crackers.
“The task force has an officer of the rank of an assistant commissioner of police (ACP), along with representatives from the BBMP, Fire and Emergency Services, Electrical Inspectorate and the Pollution Control Board. They not only seized traditional crackers but also cracked down on the illegal sale of crackers,” said the KSPCB official.